The development of polymeric contact lenses has broadened considerably the market for contact lenses. With relatively few exceptions, the wearers of such polymeric lenses find them to be more comfortable to wear than the earlier glass contact lenses.
By reason of the polymeric materials from which they are prepared, some users find that their polymeric lenses have a shorter useful life by reason of the development of deposits on the surfaces of and sometimes in the interior of the polymeric lenses. Such deposits are believed to be complex calcium containing mucin lipid proteins. Such deposits initially form on the lens surface. Unless removed, they can penetrate into the interior of the highly hydrated polymeric lens. Such deposits, when they develop, give rise to a number of problems. The deposits cause a change in the wetting angle of the aqueous eye fluids on the surface of the lenses. In addition, the interior lens surfaces become somewhat rough and the lens tends to become uncomfortable for the wearer. As such deposits build up, they cause opaque areas in the lens which interfere somewhat with the wearer's sight.
For the above reason, there is a need in the art for methods and compositions for removing such calcium containing mucin lipid deposits from polymeric lenses.